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Originally posted by plain spoken If dehumidification option is turned on, then yes as long as your humidity set point is below 60%.

You select the humidity set point just like you select your temperature set point. You can turn dehumidification off or on, again a selection.

The design of the Infinity is to provide much greater than normal dehumidification (as well as many other controls and comforts). It provides this dehumidification in seveal ways. 1. Any time you have a call for cooling (temperature above setpoint), the Infinity system operates at a lower cfm range to dehumidify. 2. If the humidity is above your set point during this call for cooling, it will slow the fan even further to do more dehumidification. 3. If you do not have a call for cooling and the humidity is above the set point, it will bring the cooling on with a very low fan speed just to dry out the air. In other words it becomes like a whole house dehumidifier. In this mode there are a couple of limits. It will only over cool the space up to 3 degrees. Once the space gets below 75 degrees then the 3 degree ovecool is proportionally decressed.

Plain,
You seem to know a lot about this subject. I have had a new Amana Ultron system installed with a two speed compressor, a two stage furnace and a varible speed blower. The installer used a White-Rodgers thermostat model 1F95-391.
This thermostat has all of the same control features you described about the Infinity. The thermostat has many points for connections but the installer only used five wires to hook up the system. My question is, is it possible to control a system with multiple speeds and stages (including humidity control) using only five wires. Thanks for any input.

I am not famaliar with that system at all so I can not help you with it. I find it hard to believe it can do all the Infinity can do, we have only discussed a very small amount of what the Infinity can do. The Infinity only uses 4 wires, so I guess it is possible yours could work with 5.

staging logic

You seem to be more knowledgeable than anyone with regards to variable speed equipment.

As such, perhaps you can tell me of the staging algorithms for the Carrier thermidistat control.

Is time the ONLY determining factor or does "progress towards the set point" count too?

For instance:

Say I am operating in the cooling mode and my set point is 72 degrees. The house temperature is 73 degrees. The stat turns the low stage of cooling on. After 15 minutes the house cools to say 72.5 degrees--does the higher stage kick in or does the lower stage continue to operate?

Scenario two:
The setpoint on the stat is 72 degrees. The temperature outside is going up quickly and the house heats up to 78 degrees. The stat turns on the high stage of cooling and the house cools to 73 degrees. Does the higher stage continue to operate until the stat is satisfied then turn the system off OR does the lower stage come on the "maintain the setpoint"?

Also--what role does the outdoor temperature sensor play with regards to staging and thermidistat operation?

Re: staging logic

You seem to be more knowledgeable than anyone with regards to variable speed equipment.

As such, perhaps you can tell me of the staging algorithms for the Carrier thermidistat control.

Is time the ONLY determining factor or does "progress towards the set point" count too?

For instance:

Say I am operating in the cooling mode and my set point is 72 degrees. The house temperature is 73 degrees. The stat turns the low stage of cooling on. After 15 minutes the house cools to say 72.5 degrees--does the higher stage kick in or does the lower stage continue to operate?

Scenario two:
The setpoint on the stat is 72 degrees. The temperature outside is going up quickly and the house heats up to 78 degrees. The stat turns on the high stage of cooling and the house cools to 73 degrees. Does the higher stage continue to operate until the stat is satisfied then turn the system off OR does the lower stage come on the "maintain the setpoint"?

Also--what role does the outdoor temperature sensor play with regards to staging and thermidistat operation?

1. If low stage is gaining toward setpoint, the unit will stay in low unless the space temperature is more than 5 degrees above set point.

2. The stat will shift the unit to low speed as it approachs set point. It is better to run in low for extended periods of time than to satisfy the call with high.

3. On the Thermidistat the outdoor sensor really has no input in the cooling mode. With a heat pump in heating mode, it does effect the staging of the electric strips and fan speed if you have Super Comfort Heat Mode enabled. It also effects the humidifier operation as well as it is used for reading the switch over temperature in a dual fuel application.

Re: Re: Two speed compressor

Originally posted by mrcoolz4u Generally when a two speed motor starts up, both winding are energized then falls back to the selected winding speed.

Actually, only the windings for the desired speed are energized. If you were to apply power to more than one of the speed taps in the motor, it would burn out the motor windings.

for example Most compressors carry two winding the start winding and the run winding. At start up both winding are energized then the start winding is taken out of the circuit leaving the run winding in the circuit.

I don't know of any compressors that drop the start winding out after startup. If it has a start kit, it will drop the start capacitor out, but the start winding will still be energized and have a run capacitor.
There are some fan motors out there that drop the start winding out after startup, but they are rare. The last one I saw was about 5 years ago on a very old 7.5 ton Westinghouse condensor with a belt driven condensor fan. A centrifical switch dropped the start winding out after it got up to speed.

At start up the amp draw is higher because both winding is drawing current. so more current is being used.

this application applies generally to all multispeed motors.

The amperage is higher at startup because the motor is pulling lock rotor amps. When induction motors start up, the amperage starts very high and goes down as it gets up to speed. It has nothing to do with how many windings are energized. Unless it is a part winding start motor, fairly rare, power is being applied to the same inputs when it is running as when it is starting...

this happens with the 3 and 4 speed motors as well. Compressors and fan motors

it starts at high speed then goes back to the selected speed.

Again, power is applied to only one speed tap at a time or bad things happen. Some higher horsepower motors used in big applications have some interesting sequences of operation, but fractional horsepower motors are started on the same speed tap/winding they are run on.

Thank you Mr mark for the correction and my appologies to anyone for posting the wrong info

Infinity

When the house was open to the humidity and reached outdoor humid temps the unit ramped up to a super highspeed mode 1600CFM then once it got closer and closer it dropped. Now most of the time it is in stealth mode and on some occasions it kicks a midspeed mode. What is weird is having a cool house but not hearing the system Also I notice that temperatures stay very consistent. Even though the system is rated 15 SEER (4ton) I suspect my savings will be higher than due to this thing running slow. I notice the outdoor meter running slowly VS real fast using the old unit which was 3 tons.

I read these new multispeed systems record the cycles and optimize them for better efficiency, Pretty interesting technology overall.